To prevent the transmission of diseases through microorganisms contained in the blood remaining in or outside used injection needles, the points of needles to be discarded are dulled so that they can not cause harm to human bodies they contact.
In the prior art, equipment is known that curls the point of a used injection needle or melts the tip of a used injection needle. An example of a known device for melting used injection needles will be described below with reference to FIG. 1. The diameter of usual injection needles varies between 0.5 mm and 2 mm. As shown in FIG. 1, a pair of fixed contacts 23 and 24 are supported by a box 82 for receiving a used injection needle. The distance between the fixed contacts 23 and 24 is approximately 0.5 mm, as shown in the figure. A third fixed contact 32 is arranged facing the gap between the first and second fixed contacts 23 and 24. An electric voltage is applied between the first fixed contact 23 and the third fixed contact 32.
When the foregoing equipment is employed, a used injection needle 9 is inserted between the first and second contacts 23 and 24 and is moved in the direction of arrow A until the lower end of the used injection needle 9 engages the third fixed contact 32 while the base of the used injection needle 9 is in contact with the first and second fixed contacts. Keeping this position, the used injection needle 9 is further pushed in the direction of the arrow A to allow an electric current to flow in the used injection needle 9 and to melt particularly the portion of the used injection needle 9 contacting the third fixed contact 32.
The first and second contacts 23 and 24 have the shape shown in FIG. 1 to facilitate insertion of a used injection needle 9. The top surface of the third fixed contact 32 is inclined to allow melted scrap to fall easily into a scrap box 31.
Protective cover 83 is arranged over the first and second fixed contacts 23 and 24 to provide safety, and this makes it difficult to see whether the base of a used injection needle 9 is in contact with the first and second fixed contacts 23 and 24. Therefore, the contact of the base of a used injection needle 9 and the first and second fixed contacts 23 and 24 is often incomplete resulting in the drawback that the electric current flowing in the used injection needle 9 is intermittent. This causes incomplete heating of the lower end of the used injection needle 9 and allows the lower end of the used injection needle 9 to curl, as shown in FIG. 3 (a) or to be deformed, as shown in FIG. 3 (b). It is difficult with the known devices to melt the used injection needle 9 substantially to the base thereof to make the end dull, as shown in FIG. 2.
The object of this invention is to provide equipment for melting a used injection needle, the equipment having the following advantages :
1. It is easy to insert a used injection needle to a position at which melting treatment is conducted.
2. The contact between the used injection needle and the fixed contacts is complete during melting whereby the used injection needle is melted substantially to the base and the point of the used injection needle is made dull, as shown in FIG. 5.